The present invention relates to an antenna for a radio communications apparatus operating in the frequency range of 800 MHz-3 GHz and including a slot provided in a metallic conductor.
In the employment of mobile radio communications apparatuses, in daily parlance mobile telephones in an urban environment, problems are often encountered in transmission and receiving. The reason for this is that, in such an environment, there are often dead zones which cannot be reached in communication with a certain cell in the system.
In order to remedy this problem, use is often made of duplicated antennae in mobile telephones, these antennae having different directive effect, polarisation and/or appearance on the antenna lobe. Such a second antenna is often entitled a diversity antenna.
The present invention has for its object to design the antenna intimated by way of introduction such that this will be suitable for use as a diversity antenna. Thus, the present invention has for its object to design the antenna in such a way that it will have a directive effect, good efficiency and, above all, extremely small dimensions so that it may be incorporated entirely into an apparatus casing. Finally, the present invention has for its object to realise an antenna which is of wide band operation.
The objects forming the basis of the present invention will be attained if the antenna intimated by way of introduction is characterized in that the slot has windings or meander formations disposed in one plane.
As a result of this feature, advantages will be afforded such as directive effect and extremely small integration dimensions.
Suitably, the antenna is also characterized in that it includes two slots disposed in substantially parallel planes, both having windings or meander formations and in which the one slot is of slightly greater length than the other.
As a consequence of these characterizing features, advantages will be afforded such as increased sensitivity and wide band capability despite the fact that the physical integration dimensions are hardly affected.
Further advantages will be attained according to the present invention is the antenna is also given one or more of the characterizing features as set forth in appended claims 4 to 14.